Mrs Kim, the sister of Kim Jong-il, the father of the current North Korean leader, was previously seen as an untouchable member of the Kim clan that has ruled the nation since 1945. That changed with the violent purges carried out by Kim Jong-un to rid his administration of "old guard" officials with perceived loyalties to his father.

In the intervening years, she has been conspicuously absent from important events on the North Korean calendar, including occasional meetings of the nation's parliament and celebrations marking the anniversary of the birthday of the founder of the nation, Kim Il-sung, her father.

Mrs Kim has long been rumoured to be in frail health. She was previously treated in Moscow for cancer, with her condition reportedly made worse by diabetes and alcoholism, as well as depression brought on by the suicide of her daughter in Paris in September 2006 after she was refused permission to marry a foreign national.